It is common to house machines, including electronic communication and computing equipment, in buildings or enclosures to protect them from the elements. However, in many instances, these machines generate heat and since it is desirable to operate such machinery only within a certain limited temperature range, this heat must be removed from the enclosure in order to avoid any adverse consequences. Furthermore, such a need for cooling is not limited solely to machines, since buildings or enclosures that house people or animals must also be cooled in order to avoid the consequences of too much heat.
One method used to achieve such cooing (and a manner employed for quite a number of years) is to force a cooling fluid, such as air, over the heat source thereby cooling the source. Of course, to avoid heat build-up within the enclosure, such cooling fluid must also be forced or vented from the enclosure.
In those cases where it is desirable for the enclosure or the equipment to remain isolated from the ambient environment, heat exchangers are needed to transfer the heat generated within the enclosure to the cooling fluid (air) outside the enclosure. In the past, these types of heat exchangers, such as shell and tube, plate, heat pipe, etc., have been employed to separately transfer the heat between the enclosed heat source and the outside cooling medium. However, in order to operate properly, these types of heat exchangers use one or more fans to force air across their surfaces. In severe cases where such simple cooling by fans is not acceptable, such as in areas of high ambient temperature, heat is removed from such enclosures by a traditional refrigeration cycle. However, both this refrigeration method and the fan-cooled method described above require a power hook-up along with many moving parts and motors for operation. Since, in some cases, power is not available at the enclosure or access to replacement parts is difficult to obtain, such methods of cooling cannot be employed. In these cases, passive cooling systems that contain no moving parts and which require no external power source are desirable in order to maintain the optimum enclosure temperature.
It is thus an object of this invention to provide a passive cooling system that does not require an outside power source for operation. Another object of this invention is to provide a passive cooling system that has no moving mechanical parts which require routine maintenance and repair. Yet another object of this invention is to provide a cooling system that is self regulating such that it automatically absorbs heat from the enclosure without requiring operator intervention. A further object of this invention is to provide a means of cooling an enclosure that only permits the removal of heat from the enclosure and does not allow (with little exception) any heat to enter the enclosure. Yet another object of this invention is to provide a system that is self-regenerative and which does not take up any valuable floor space. Still another object of this invention is to provide a cooling system that enables the enclosure to avoid contact with the ambient environment thereby achieving a clean and relatively dust-free enclosure. These and other objects and advantages of this invention will become obvious upon further investigation.